how to say “button-down shirt” in Hebrew
חֻלְצָה מְכֻפְתֶּרֶת
The Hebrew word for shirt is חֻלְצָה 
listen and repeat. And the word for button is כַּפְתּוֹר listen and repeat.
listen and repeat. And the word for button is כַּפְתּוֹר listen and repeat.To form button-down or that which is made with buttons, Hebrew plugs כפתור into the passive-intensive verb form to yield מְכֻפְתָּר listen and repeat in the masculine and מְכֻפְתֶּרֶת listen and repeat in the feminine.
listen and repeat in the masculine and מְכֻפְתֶּרֶת listen and repeat in the feminine.אִם אַתָּה לֹא לוֹבֵשׁ חֲלִיפָה, לְפָחוֹת תִּלְבַּשׁ חֻלְצָה מְכֻפְתֶּרֶת!
If you’re not wearing a sports jacket, at least put on a button-down shirt! (to a male)
While I gave examples using the grammatically-correct way of pronouncing these words, you’re more likely to hear Israelis saying מְכֻּפְתָּר listen and repeat and מְכֻּפְתֶּרֶת listen and repeat.
listen and repeat and מְכֻּפְתֶּרֶת listen and repeat.